Subject: SCF Convergence problem in G03

From: "Tapas Kar" <tapaskar.-at-.cc.usu.edu>
Date: Wed, 4 Aug 2004 16:49:49 -0400

Hi experts,

I am getting SCF convergence problem with single-point calculations on large
C200-O3 to C260-O3 systems using B3LYP/6-31G* basis in G03. I tried
vshift=300, SCF=QC  and different guess with no luck. Also tried anion(-2)
and cation (+2)of the same.  Energy is highly oscillating from one step to
other, even +/- 20au. Is there any option in G03 to get my job done. Gamess
looks don't allow more than certain number of basis functions.

Thanks

Tapas

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"We owe a lot to the Indians, who taught us how to count, without 
which no worthwhile scientific discovery could have been made." 
                                           - Albert Einstein -
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Tapas Kar, Ph. D
Department of Chemistry & Biochemistry
Utah State University
Logan, UT 84322-0300

Tel: 435-797-7230
Fax: 435-797-3390
Email: tapaskar.-at-.cc.usu.edu
Web: http://www.chem.usu.edu/faculty/Tapas/index.html
         http://www.chem.usu.edu/~tapaskar/index.html